Change background color in Black Letterhead?

I would like to move my blog over to the Black Letterhead theme, but change the entire background (to white #FFFFFF). Subsequently, change the color of the type (to simple black #00000), the post titles, etc. Switch everything around.

It seems easy to do with the CSS upgrade, which I have, but I'm sort of a complete noob so I don't know the exact code...

I know I marked this topic as resolved, but something new came up and I'll appreciate all the help I can get...

What can I do to fix the comments? Because it was originally supposed to be an über-dark background, all the colors are thrown off and the text is sometimes unreadable. You can find what I'm talking about here.

That is because the comments inherit the font colors from the "a" and "body" declarations, and the code that @iww4n gave didn't account for that thus turning everything black. Add the following to turn the font color in comments back to white.

.commentlist {
color: #FFFFFF;
}
.commentlist a {
color: #FFFFFF;
}

The top is the comment content text, and the bottom bit is the username and date color in case you want different colors for each.